THE VAST MAJORITY OF ELECTRICITY AMR SYSTEMS DEPLOYED IN THE UNITED STATES TO DATE USE ONE-WAY COMMUNICATIONS TECHNOLOGY. This technology allows utilities to obtain meter readings without a line of sight to the meter by using a handheld reading device equipped with an RF receiver, or by collecting data remotely via the power line.
When demand meters are part of one-way AMR systems, there is no way to signal the meter to reset demand once the billing data is read. Therefore, in saturated cells of residential meters, demand meters are often still read manually because pressing the demand reset button signals the meter to end the current billing period and begin the next billing period. This is costly to the utility due to less efficient read routes.
It is American Electric Power's (AEP's) position that the largest operational issue is programming meters with a calendar that matches its cycle read. This means that before a meter is deployed it must be programmed to reset on a specific date schedule with consideration to the meter-read cycle of which it is installed. If a meter is redeployed, reprogramming is necessary. Recognizing this challenge, AEP approached GE to look for ways to resolve this issue. It was important for AEP to maintain the ability to read meters early when needed, and the two companies worked to develop a solution to make reading demand meters “cycle insensitive.” A proprietary algorithm was created to solve this problem.
GE realized that making reading demand meters cycle-insensitive would require a new way of selecting the maximum demand for the billing period. A meter programmed for cycle-insensitive demand calculates demand at the end of each typical demand interval (block, rolling, thermal). However, instead of comparing the new demand against the maximum demand, the meter keeps track of the daily demand. At the end of the day, the daily demand is saved. The meter keeps track of the last 35 daily demands, dropping the oldest and adding the most recent data.
With this solution, the meter reviews its daily peaks to find two peaks that it will report for the next 24 hours. The first peak should be configured for the average number of business days between cycle reads and is typically set to 21 business days. This will be used when the meter is read on time or late. The second peak is used for cases when the billing period is short, either because it was read late last month or it is read early the current month. This is typically set to 18 or 19 business days.
When AEP's installation of cycle-insensitive meters is complete, the business will have flexibility it didn't have previously. The company can also move meters to a different route without reprogramming the calendar, and it only needs to maintain a single calendar. Specifically AEP can:
Calculate the proper monthly demand without a program in the meter to reset the meter on a particular read schedule.
Calculate a secondary demand that will allow for early reading when required.
Provide alarms, alerts and quality-of-service metrics.
Support the demand data needed for residential move-ins and move-outs that allow for the extraction of the peak demand between two dates.